1. Field of the Invention
The present invention relates to a printing apparatus, equipped with a tray that is pivotally mounted between an open and a closed positions in order to hold printed sheets, and a control method for the printing apparatus.
2. Description of the Related Art
Generally, a tray (a discharge tray) wherein printed sheets of a material (e.g., printed sheets of paper) are held is provided for a printing apparatus. Such a discharge tray is pivotally mounted on a rotary shaft, between an open and a closed position, and can be closed when not in use, both to reduce the external size of the printing apparatus and to prevent foreign matter, such as dust, from entering and degrading the function of the printing component of the apparatus. However, when printing is inadvertently begun while the discharge tray is closed, the discharge tray will interfere with the discharge of printed sheets, and internal printing apparatus problems, such as paper jams, will occur.
To avoid this problem, a printing apparatus proposed in Japanese Patent Laid-Open No. 2010-6608 includes a control mechanism, whereby a discharge tray is automatically opened when the printing of sheets is performed and the rotation of discharging rollers is begun. The control mechanism includes a delay mechanism that provides a predetermined delay before the rotation of the discharging roller is transmitted to the discharge tray. Further, at present, like a printing apparatus disclosed in Japanese Patent Laid-Open No. 2010-6608, the same drive source is employed for a conveying roller and a discharging roller to reduce the size and the manufacturing cost of the printing apparatus.
However, according to the printing apparatus described in Japanese Patent Laid-Open No. 2010-6608, which includes a discharge tray delay mechanism, in a case wherein an error has occurred under the condition whereby the length of delay is accumulated in the delay mechanism, even when the error has been corrected, and printing is thereafter restarted, the timing for the opening of the discharge tray may not be appropriate. This occurs, for example, during an operation whereby the printing apparatus corrects the positional deviation of a sheet of paper by causing the leading edge of the sheet to abut against a reversely rotating conveying roller. At this time, when the same drive source is employed for the conveying roller and the discharging roller, as described above, the discharging roller is also reversely rotated in association with the reverse rotation of the conveying roller, and the length of the delay is accumulated in the discharge tray delay mechanism. Assume that under a condition such that the length of a delay is accumulated, the printing apparatus is halted due, for example, to an “Out of Paper” error. In this case, when the error has been corrected and the feeding of paper is sequentially restarted, as in the normal state, the discharge tray may be opened later than the intended time because of the length of the accumulated delay.
In a case wherein the discharge tray is opened following a delay, as described above, the following problem would occur.
(1) A sheet of paper to be delivered may be bent by striking the discharge tray in the closed state.
(2) The discharging roller is rotated at a low speed at the opening timing for the discharge tray; however, since the opening timing is delayed, the discharging roller will be rotated at a high speed that is appropriate for printing, and as a result, the discharge tray will be opened suddenly and rapidly.